I'm thinking on how to charge the capacitors in the first place. I can't charge them from track power without a totally isolated power source as the DCS or Legacy electronics doesn't have a common DC ground. One possibility is to charge them from the same place I'm providing the power when track power is gone, but I have to deal with the issue of not charging when the caps are powering the electronics.
Hey John, the caps will charge as long as the engine is powered, provided the output voltage of the boost regulator is set correctly, as I describe in the other thread. Since they are powered after the rectifier in the decoder it doesn't matter if the track power is AC, DCS, DCC, or whatever. The power/ground for the keepalive is internal to the decoder.
Am I misunderstanding your question?